In order to conform the function requirement of computer equipment, an expansion board is often added into a master circuit board, such as motherboard, inside the computer equipment. FIG. 1 is a stereoscopic construction diagram of an expansion board being added into a master circuit board according to the prior art. As shown in FIG. 1, the computer equipment comprises a master circuit board 51. The master circuit board 51 is provided thereon with a plurality of connecting seats 511 conforming to specific transfer specification, such as the connecting seat conforming to PCIe transfer specification. When the computer equipment desires to expand the function, a connector 521 of an expansion board 52 will be inserted into the connecting seat 511 of the master circuit board 51 so as to expand the function of the computer equipment.
In the past, the connector 521 is often disposed on an underside edge of the expansion board 52. Therefore, the expansion board 52 will be perpendicular to the master circuit board 51 when the connector 521 of the expansion board 52 is inserted into the connecting seat 511. Accordingly, the computer equipment must be provided with a space capable of accommodating the expansion board 52 inserted into the master circuit board 51 in a perpendicular direction, in such the way that will be a barrier for the current computer equipment desirous of light, thin, short and small characteristics.
As shown in FIG. 2, otherwise, the connector 541 is selectively disposed on a horizontal surface of the expansion board 54. Therefore, the expansion board 54 will be stacked on the master circuit board 53 to form a spliced appearance when the connector 541 of the expansion board 54 is inserted into the connecting seat 531 of the master circuit board 53. Although the volume that is constituted based on the expansion board 54 inserting into the master circuit board 53 by adopting the spliced way is able to decrease, the master circuit board 53 only allows single expansion board 54 to insert therein, resulting in the expansion of function of the master circuit board 53 will be limited.